PersistentMap<K, V> class

PersistentMap used a DBM database to provide an implementation of the dart Map interface which transparently saves the Map to disk

Implemented types

• Map<K, V>

Constructors

PersistentMap(DBM _dbm, Uint8List _keySerializer(K), K _keyDeserializer(Uint8List), Uint8List _valueSerializer(V), V _valueDeserializer(Uint8List), {bool valueComparator(V, V)?})

Create a new PersistentMap, with the underlying dbm database, key and value serialization functions, and an optional value comparator.

Properties

entries → Iterable<MapEntry<K, V>>

The map entries of this Map.

no setter, override

hashCode → int

The hash code for this object.

no setter, inherited

isEmpty → bool

Whether there is no key/value pair in the map.

no setter, override

isNotEmpty → bool

Whether there is at least one key/value pair in the map.

no setter, override

keys → Iterable<K>

The keys of this Map.

no setter, override

length → int

The number of key/value pairs in the map.

no setter, override

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

values → Iterable<V>

The values of this Map.

no setter, override

Methods

addAll(Map<K, V> other) → void

Adds all key/value pairs of other to this map.

override

addEntries(Iterable<MapEntry<K, V>> newEntries) → void

Adds all key/value pairs of newEntries to this map.

override

cast<RK, RV>() → Map<RK, RV>

This method is not implemented by this map implementation and will result in an exception being thrown.

override

clear() → void

Removes all entries from the map.

override

close() → void

Close this database

containsKey(dynamic key) → bool

Whether this map contains the given key.

override

containsValue(dynamic value) → bool

Checks to see if the map contains a value. The result of this is dictated by the comparator function passed when creating the PersistentMap and uses it to check every entry value until a match is found. The function should therefore be capable of deep comparisons for structured types. Given that this function will check every value until a match is found it can potentially have significant performance impact.

override

forEach(void action(K key, V value)) → void

Applies action to each key/value pair of the map.

override

map<K2, V2>(MapEntry<K2, V2> convert(K key, V value)) → Map<K2, V2>

Map from a PersistentMap to a memory-resident map created by applying a mapping function to each key-value pair.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

putIfAbsent(K key, V ifAbsent()) → V

Look up the value of key, or add a new entry if it isn't there.

override

remove(Object? key) → V?

Removes key and its associated value, if present, from the map.

override

removeWhere(bool test(K key, V value)) → void

Removes all entries of this map that satisfy the given test.

override

toString() → String

A string representation of this object.

inherited

update(K key, V ifPresent(V value), {V ifAbsent()?}) → V

Updates the value for the provided key.

override

updateAll(V update(K key, V value)) → void

Updates all values.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

operator [](Object? key) → V?

The value for the given key, or null if key is not in the map.

override

operator []=(K key, V value) → void

Associates the key with the given value.

override

Static Methods

make<K1, V1>(File file, Uint8List keySerializer(K1), K1 keyDeserializer(Uint8List), Uint8List valueSerializer(V1), V1 valueDeserializer(Uint8List), {bool create = false, bool comparator(V1, V1)?}) → PersistentMap<K1, V1>

Create a PersistentMap with K1 for keys and V1 for values, with file being the database file, and create specifying whether to create a new file if it doesn't exist. If file already exists, the file will not be overwritten, but rather opened. The serializers for the keys and values must be provided when calling this function. If file contains and incompatible database, behavior is unspecified.

withMapValue(File file, {bool create = false, bool comparator(Map<String, dynamic>, Map<String, dynamic>)?}) → PersistentMap<String, Map<String, dynamic>>

Create a PersistentMap with strings for keys and maps for values, with file being the database file, and create specifying whether to create a new file if it doesn't exist. If file already exists, the file will not be overwritten, but rather opened. If file contains and incompatible database, behavior is unspecified. Note that the value must be convertible using the json functions in dart:convert

withStringValue(File file, {bool create = false}) → PersistentMap<String, String>

Create a PersistentMap with strings for keys and values, with file being the database file, and create specifying whether to create a new file if it doesn't exist. If file already exists, the file will not be overwritten, but rather opened. If file contains and incompatible database, behavior is unspecified.